Tuesday, July 12, 2005

The Question of Biosolids

"I can appreciate peoples concern over the human waste issue. Thirty years ago I lived in South Korea were unproccessed human waste was used almost exclusively for fertilizer. The stench was terrible. We were not allowed to eat the vegetables because of contamination. But that was 30 years ago. Today biosolids are processed and a resource we should use. Fertilizer prices are going to increase with the fuel that is used to produce them. And from what I have read there is no longer a stench or the threat of contamination with biosolids. "

I was in error in saying there is no longer a stench. A look at the EPA website reveals:

"Once the wastewater reaches the plant, the sewage goes through physical, chemical and biological processes which clean the wastewater and remove the solids. If necessary, the solids are then treated with lime to raise the pH level to eliminate objectionable odors. The wastewater treatment processes sanitize wastewater solids to control pathogens (disease-causing organisms, such as certain bacteria, viruses and parasites) and other organisms capable of transporting disease. "

There is still an odor issue as further stated by the EPA. However, I still support the use of biosolids as a natural way to fertilize and its other uses. To read more go to the EPA faqs on this issue.

I do not how how you can state that "no one clearly knows, biosolids have been used for centuries. In fact raw sewage which is dangerous is sometimes used in growing the food imported to America.

Human waste naturally decomposes and is filled with soil nutrients. You are talking about a natural process. What is unnatural is the use of man made fertilizers, which does not add structure to the soil, which biosolids do.

It is true that in the process of decompositon there are pathogens that would be in biosolids. Basically, these are germs. In the natural rendition of biosolids it takes time for many of these pathogens to be killed by the amonia and methane that also develops.

The only difference between how sludge is processed is that this process is speeded up. Class A biosolids reach a point when the level of nitrogent, amonia, and methane does not allow pathogens to exist.

In Class A Biosolids this process is complete, and is no more dangerous than the ground you walk on. And by the way, pathogens are are always in dirt.